Evaluation of a new high-strength aluminous porcelain

Abstract

The strength and degree of firing shrinkage of a new dental core porcelain have been investigated. The disc strength was found to be significantly greater than that of conventional aluminous porcelain. The new material also exhibited reduced firing shrinkage. An examination of the microstructures of both high strength and conventional core materials was carried out using back-scattered electron microscopy. This study revealed that the stronger porcelain contained a greater concentration of alumina crystals. Since the tensile strength of dental porcelain is dependent on surface condition, the appearance of the porcelain surface was examined. Porcelain fired on both a refractory model and platinum foil was compared using scanning electron microscopy. Good adaptation was achieved in part with platinum foil, although a large number of irregular open pores were observed. A rougher, though less porous, surface was produced by the refractory model method.